SCH Number 2020120459

Project Info

Title

Upper Mormon Slough Erosion Repair Project

Description

The proposed project would consist of repairs to the north and south banks of the upper segment of Mormon Slough near the Escalon-Bellota Bridge in San Joaquin County, California. Mormon Slough accepts flow from the Calaveras River at Bellota and carries it to the Stockton Diverting Canal, which returns the flow to the Calaveras River. Project activities include the removal of compromised material in the channel and repairing the channel slope with a variety of materials including soil-filled rock slope protection (RSP), a coarse filter bed, earthfill, and launch rock. The repairs would consist primarily of installing RSP, which generally consists of rip-rap of varying size, soil, gravel and a textile fabric above the ordinary high water mark to prevent downward migration of the soil. To promote growth of vegetation, the RSP voids would be filled with agricultural soil and seeded with grasses (i.e., soil filled RSP). Excavation prior to placement of RSP would generally be limited to removal of loose surface debris from past slope failures, minor grading to produce relatively smooth surfaces to prepare for RSP, or to key the repairs into the existing slopes. After grading, workers would install a coarse sand or gravel filter bed that will seal cracks or openings in the base soil. A base of launch rock would be installed at the lower edge of the filter, and RSP would be laid over the filter bed.

4 documents in project